After an NBC producer recovered the tape, senior network executives became involved in the talks about how and when to broadcast it. Legal questions were reportedly a concern, but executives had made the decision to go ahead and air it on "Access Hollywood" and NBC's newscasts.

But the network was ultimately scooped by the Washington Post, which obtained a copy of the tape on October 7 and posted it online. It is unknown how the tape leaked.

The tape shocked many listeners, caused some Republicans to distance themselves from Trump, and seemed to hurt him in some polls.

O'Reilly asked him on Thursday, "Do you think you would be ahead if not for the 'Access Hollywood' stuff?"

"I just don't know. I think it was very negative, it was locker room talk," Trump said.

Trump could have stopped his answer there, but he continued: "The microphone was not supposed to be on, not that I make that as an excuse for myself, but certainly it was an illegal act from NBC."

Trump said it was "absolutely" illegal because "that was a private dressing room."

Trump and Bush were on board an NBC-branded bus when they were recorded. They were there to tape a TV segment.

Trump only alluded to possible legal action after O'Reilly asked, "Are you going to take any action after the election?"

Trump's answer was "We're going to find out soon enough."

Trump has a reputation for talking about possible lawsuits but not following through. While he does, in fact, sometimes sue people, he frequently does not.

Earlier this month, Trump aides said he was preparing a lawsuit against The New York Times for publishing accounts from two women who accused him of unwanted advances.